Gas-engine



(No Model.) 4 Sheets-Sheet 1,

S. WITHERS & DESTAING'S. COVERT. GAS ENGINE.

No. 487,313 Patented D00. 6, 1892.

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4 Sheets-Sheet .3.

(No Model.)

GAS ENGINE.

Patented Dec. 6, 1892.

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a a v (No Model.) 4 Sheets-Sheet 4.

S. WITHERS & DESTAING S. COVERT.

GAS ENGINE.

' Patented Dec. 6, 1892..

1 Him Ill i I l \a 52 nllw H m 2%?26666 I 157%? y WM 4 a@- UNITED STATES PATENT SAMUEL \VITIIERS, OF LONDON, ENGLAND, AND DESTAING SALISBURY COVERT, OF CHICAGO, ILLINOIS.

GAS-ENGINE.

SPECIFICATION forming partof Letters Patent No. 487,313, dated December 6, 1892.

Application filed October 12, 1891. Serial No. 408,447. (No model.)

To all whom it may concern:

Be it known that we, SAMUEL \VITHERS, a subject of the Queen of Great Britain, residing at London, England, and DESTAING SALISBURY COVERT, a citizen of the United ence being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this specification.

Our invention relates to gas-engines, and particularly to that class of engines in which oscillating pistons are used; and it consists of a duplex engine comprising two singleacting engines acting in alternation, their pistons being rigidly connected and having common trunnions, the cylinder-chambers being so united that each piston while under pressure from the explosion compresses the next charge for the other engine, suitable valve mechanism being provided to control the induction, the transfer of the charges, and

the eduction.

In the accompanying drawings, Figure 1 shows an end elevation of the engine. Fig. 2 is a vertical longitudinal section on line 2 2, Fig. 1. Fig. 3 is adetail of a portion of the mechanism for operating one of the valves. Fig. i is a vertical transverse section on line 4 4, Fig. 2. Fig. 5 is a vertical longitudinal section on line 5 5, Fig. 4. Fig. 6 is a detail of a portion of the shell of the cylinder. Figs. 7 and 8 are end and side views, respectively, of the engine, showing certain modifications. Fig. 9 is a vertical section on line 9 9, Fig. 8; and Fig. 10 isa plan view on line 10 10, Fig. 8.

A drum-shaped cylinder Ais used, the flat sides E of which are secured to the circular portions by suitable bolts. The shell of the cylinder is cored to form water-chambers X X, both in the cylindrical portion and in the flat heads. These water-chambers are fed by the means common in gas-engines, which means we have not deemed it necessary to show.

The interior of the cylinder A is divided into segmental chambers K'K by bulk-heads B B, which may either be cast integrally with the shell or fitted therein. The bulkheads should be opposite each other, and we prefer to locate them at the top and bottom of the cylinder, as shown. Piston-blades O G are mounted upon and rigidly fixed to the trunnionsD, common to both. These pistons O O are of such shape as to fit snugly within the chambers K K and have frictional contact with their walls, so as to oscillate between the bulk-heads B B.

Our improved engine is designed to be operated by a succession of explosions of gas within the chambers K K. The successive charges are introduced through the duct N and their introduction is controlled by the rotating valve L, located in the bulk-head B. A recess T is formed in the side of the valve L, so as to bring the duct N in communication alternately with the duct N, leading to the chamber K, and with the duct N leading to the chamber K.

The successive charges of explosive gas are drawn into the engine by suction. With the valve in the position shown in Fig. 4 a charge is about to be introduced into the chamber K during the return stroke of the piston C. At the end of this strokethe valve L is so shifted by means of the mechanism hereinafter described as to bring the channels N and N into communication, so that the next charge will be delivered to the chamber K. Ducts 0 0 formed in the cylinder-heads E by cor ing, lead from the seat of the valve L to the chambers K K, respectively, opening therein below the pistons O and C. A passage T is formed in the valve L, so as to register simultaneously with the channelsO and N and with the channels 0 and l The relative position of the ducts N,N,N O, and O asthey open to the seat of the valve L and of the recessT and passage T is such that when the duct N is in commuication with theductN'theductsN and O are connected by the passage T and when the duct N is open to the duct N the ducts N and O are in communication. As the piston O ascends from the position shown in Fig. 4: tl:e contents of that portion of the chamber K which is above the piston are driven through the channels N T 0 into that p01 tion of the chamber K which is below the piston C. The bulk-head B being of less thickness than the. bulk-head B, neither piston reaches it in its return stroke, so" that when the piston has reached its lowest position there remains a space between it and the bulk-head B. Into this space the charge driven from above the opposite piston is compressed. When the piston is at its lowest point, the charge below it is fired, and as a result the piston is driven upwardly.

The ignition devices shown consist of tubes U U, extending outwardly from the lower parts, respectively, of the chambers K K and having their outer ends closed A fiame is constantly burning in proximity to these tubes, the gas being provided for that purpose by means of the pipes U U A thin metal flap o" is secured to the under side of each of the pistons near its outer extremity andbent so as to extend along and slide upon the inner curved wall of the cylinder a suitable distance. Asthe charge is compressed below the piston, this metal flap covers the open end of the tube U or U until the piston has reached its lowest point, when, an aperture through the flap o registers with the open end of the tube and permits the gas, now highly compressed, to enter the tube, where itis ignited by the high temperature of the latter and inflammation is communicated to the body of the charge. While the manner of applying this ignition device to our engine is novel, we. do not wish to be limited ,to this method of ignition, as it is obvious that other and Well-known ignition devices, especially electrical, could be as readily applied.

The exhaust mechanism consists of the rotating valve L located in the bulk-head B, the ducts P and P, leading, respectively, from the chambers K K through the bulk-head B to the seat of the valve, the exhaust-duct M, communicating from the seat of the valve L to the exterior of the cylinder, and arecess T? in the side of the valve L which is adapted to bring the ducts P and P alternately into communication with the duct M.

The valve L is operated by mechanism hereinafter described in such manner that'as the piston O descends in its return stroke from the position shown in Fig. 4 an outlet is provided for the burned gases below it through the duct M until the piston has traveled approximately one-half of its stroke. The valve is now shifted so that the duct M is not in communication with either of the cylinder-chambers and remains in that position until the piston C'commences its return stroke, when it is again shifted to. open communication between the chamber K and the duct M. .It remains in thisposition until the piston O has completed about on'e half of its return stroke, when it is shifted back tothe intermediate position again, from which it is once more changed, so as to open the exhaust from the chamber K,

Eacjh charge admitted to the engine is stratified, that entering at the commencement of the return stroke of the piston being highly explosive. When the return stroke is approximately one-half completed, the gas is shut off and the remainder of the charge consists of pure air. Upon the outstroke of the piston the air is first driven from before it to the portion of the opposite cylinder-chamber backof its piston, for the purpose of driving out the gases resulting from the previous explosion. The exhaust-port of the chamberin which the piston is descending is closed before any part of the charge in which there is an admixture of gas is admitted to it.

For the purpose of controlling the stratification of the charge a four-way rotating valve n is placed in the service-pipe N which is smaller than and opens into the duct N, space being left for the free admissionof air into the duct N The valven is operated by means of a crank-arm n, fixed. to it, a crankarm n fixed to the trunnion D, and a connecting-link n uniting them, these crankarms being so adjusted that the valvenis open during the first half of the stroke of the pistons and closed during the last half of their stroke. A different and a preferredform of valve for securing a ,stratification of the charge is shown in Figs. 7, 8, 9, and 1 0. A puppet-valve N cuts off gas from theservicepipe nlflthe ,valve being held to its. seat by spiral spring N and being forced therefrom by a crank-armn bearingagainstthe end of its spindle n The crank-arm n is rigidly attached to a rocking bargjournaled in suitable bearing-blocks b, bolted to. the shellA. A second crank-arm n is rigidly attached to the same barand jointed to the link 01. which connects with, theswinging lever n pivoted toa bracket a which is bolted to the standard Z. The pivot-pin connecting the link 7& and the lever also carries a roller m which bears upon a cam 91 keyed upon the crank-shaft h, the roller 11 being held to the cam by aspri-ng or, attached to the lever n and the standard Z. The cam n is provided with two equidistant circumferential projections, which have the elfect of lifting the link m twice in each re'voQ- lution, so that the valve n is openedand closed. twice in each revolution. The form and adjustment of the cam n? are such that the valve n? is open during the first halt'pf the stroke of each of the piston-blades. The ports n are provided for admitting a suitable supply of air into the journal.

Crank-arms J are fixed to the outer ends of the trunnion D andconnected by means of the spindles G G with the wrist-pin F of the crank-shaft h, whose crank-arms H are of such,

length that the diameter of the cycle of the wrist-pinv F is equal to the stroke of the pivotpin I, uniting the crank-arm J and the spin"- dle G. By means of this mechanism the oscillating motion of the crank-arm J is transformed, into rotary motion. The balance wheel Y is mounted upon the shaft h. This shaft is journaled in suitable boxes in the standard 'Z, upon which the entire engine is mounted.

The mechanism for operating the valve L consists of a crank-arm Z, rigidly fixed to the stem of said valve and pivotally connected with a vertical spindle S which has a reciprocating motion in a suitable bearing in the bracket 25, which extends upwardly from the body Z. The lower end of the spindle S rides upon a cam f, which is keyed to the shaft h, and is of such shape as to communicate to the valve its required movements, and is suitably timed with reference to the movements of the pistons. A spiral spring 3 unites the crankarm Z with the bracket i, so as to hold the spindle S firmly against the cam f.

The mechanism for operating the valve L consists of a stem Z standing out from the end of the valve and supported by a bracket Z and carrying a bell-crank, one arm S of which is actuated by a cam f, keyed upon the shaft h, and the other arm S of which is united with the standard Z by a spring 3, for the purpose of holding the arm Sagainst the cam. The cam f is of such form and so timed as to give the valve its desired movement.

It will be advisable to seat the valves L and L fin-bushings, as shown at Z Z.

WVe have described and shown two cranks J J With suitable connection with the crankshaft. It is obvious that one of them may be dispensed with, although in our judgment the engine will run more smoothly with two.

Ve claim as our invention 1. In a duplex gas-engine, the combination of two alternating single-acting engines having oscillating pistons, induction-ports in the end of the cylinder-chambers remote from the seat of explosion, ducts uniting the opposite ends of the cylinder-chan1bers, valves for controlling the induction ports and ducts and adapted to close the induction-port of each cylinder during the pressure-stroke and to open it during the return stroke of its piston and to open the duct-opening behind the returning and before the advancing piston, eduction-ports leading from each cylinderohamber behind its piston, and valves for con.- trolling said ports and adapted to open the same during the first one-half of the return stroke of the piston, substantially as described.

2. In a duplex gas-engine, the combination, with two alternating singleacting engines,

each adapted to draw in a new explosive charge after its returning piston and force that charge behind the piston of the other engine during the succeeding stroke, of ignitiontubes opening into the explosion-chambers behind the pistons, gas-burners for heating said tubes, flaps, as i2 12, attached to the pistonsand sliding on the surface of the explosionchamber and adapted to cover theinner ends of the ignition-tubes and having apertures, as w 20, adapted to register with the mouths of the tubes at the end of the return strokes of the pistons, substantially as described.

3. In aduplex gas-engine, the combination, with a pair of alternating single-acting plston engines having ducts uniting the opposite ends of the two cylinder-chambers and valve mechanism adapted to open the duct leading from before the advancing piston to behind the returning piston, of an inductionduct for each cylinder-chamber, located on the side of the piston remote from the seat of inflammation and opening externally, valve mechanism adapted to open the inductionducts during the return strokes of'the pistons and close them during their out or power stroke, gas-supply pipe opening into the induction-ducts, valve mechanism for opening the gas-pipe during a part only of each return stroke of the pistons, eduction-ducts leading from the cylinder-chambers behind the pistons, and valve mechanism for opening the eduction-ducts during a part of the return strokes of the pistons, substantially as described.

4. In adupleX gas-engine,the combination, with a pair of .alternating single-acting piston engines having ducts uniting the opposite ends of 'the two cylinder-chambers and induction-ducts leading to the ends of the cylinder-chambers remote from the seat of inflammation, of eduction-ducts leading from the ends of the cylinder-chambers at which inflammation occurs and valve mechanism for opening the eduction-ports during a portion only of each return stroke of the pistons, substantially as described.

SAMUEL WITHERS. DESTAING SALISBURY COVERT.

WVitnesses:

OHAs. A. ALLISON, WILLIAM T. ELLIOTT. 

